I personally don’t recommend Robinhood if you are serious about trading. As of this writing, the app has very basic functions and I’ve heard horror stories about their system being down for long periods of time.
Schwab Street Smart Edge is a solid platform which I like to use for scalping. The interface is a bit clunky and seems outdated, but its execution is fast and solid.
TastyWorks is my favorite platform to trade options. Although it’s missing some advanced complex order features, it makes up for it with its fast execution and great interface that makes it easy to visualize your options strategies. Their support is also great. You can chat with them, email them, call them. Every time I’ve had an issue they fixed it right away.
ThinkorSwim is one of the most complete platforms in terms of charts, scanners and complex orders plus it has all the bells and whistles. Having said that, TOS was built in Java many years ago and at times it gets laggy and slows down even with the most up to date computers. One workaround I found is to open several instances.
I use all of the above mentioned platforms on a daily basis and I like each one for different reasons. Thinkorswim is the only one that I know of that has a Paper Money feature so you can practice trading with virtual money.